全文获取类型
收费全文 | 45100篇 |
免费 | 4522篇 |
国内免费 | 3615篇 |
专业分类
耳鼻咽喉 | 386篇 |
儿科学 | 479篇 |
妇产科学 | 620篇 |
基础医学 | 5435篇 |
口腔科学 | 999篇 |
临床医学 | 5931篇 |
内科学 | 6758篇 |
皮肤病学 | 512篇 |
神经病学 | 2357篇 |
特种医学 | 1713篇 |
外国民族医学 | 20篇 |
外科学 | 4665篇 |
综合类 | 7732篇 |
现状与发展 | 15篇 |
一般理论 | 6篇 |
预防医学 | 3061篇 |
眼科学 | 1202篇 |
药学 | 4635篇 |
28篇 | |
中国医学 | 2803篇 |
肿瘤学 | 3880篇 |
出版年
2024年 | 147篇 |
2023年 | 685篇 |
2022年 | 1814篇 |
2021年 | 2253篇 |
2020年 | 1732篇 |
2019年 | 1457篇 |
2018年 | 1587篇 |
2017年 | 1459篇 |
2016年 | 1347篇 |
2015年 | 2000篇 |
2014年 | 2542篇 |
2013年 | 2180篇 |
2012年 | 3186篇 |
2011年 | 3485篇 |
2010年 | 2108篇 |
2009年 | 1743篇 |
2008年 | 2233篇 |
2007年 | 2297篇 |
2006年 | 2264篇 |
2005年 | 2059篇 |
2004年 | 1698篇 |
2003年 | 1818篇 |
2002年 | 1630篇 |
2001年 | 1386篇 |
2000年 | 1221篇 |
1999年 | 1311篇 |
1998年 | 879篇 |
1997年 | 805篇 |
1996年 | 635篇 |
1995年 | 581篇 |
1994年 | 510篇 |
1993年 | 259篇 |
1992年 | 352篇 |
1991年 | 290篇 |
1990年 | 271篇 |
1989年 | 220篇 |
1988年 | 212篇 |
1987年 | 175篇 |
1986年 | 147篇 |
1985年 | 91篇 |
1984年 | 76篇 |
1983年 | 33篇 |
1982年 | 18篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
针对厨余垃圾特点,设计节水、能耗低、能有效控制异味扩散的餐厨垃圾破碎-真空管道输送系统,并对不同输送方式进行优化研究。 相似文献
982.
Purpose: RNA helicase p68 plays an important role in organ development and maturation through tuning cell proliferation. However, the character and role of p68 in the whole wound healing process need more study.
Methods: First, we characterize expression of p68 in normal rat skin development postnatal. Then, we assayed dynamic change of p68 in rat skin from different stage after injury, and explored the role of p68 in proliferation and migration of three types of wound healing related cells.
Results: p68 was down-regulated during skin developmental and maturation process, up-regulated after wound, peaked on day 14 and then significantly decreased. Wound fluid enhanced wound healing related cell proliferation and up-regulated expression of p68. Conversely, reducing p68 expression by RNA interference resulted in significantly slower proliferation and migration.
Conclusion: Our results define an important role of RNA helicase p68 in skin wound healing process. 相似文献
983.
984.
Pre‐ischemia melatonin treatment alleviated acute neuronal injury after ischemic stroke by inhibiting endoplasmic reticulum stress‐dependent autophagy via PERK and IRE1 signalings
下载免费PDF全文
![点击此处可从《Journal of pineal research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dayun Feng Bao Wang Lei Wang Neeta Abraham Kai Tao Lu Huang Wei Shi Yushu Dong Yan Qu 《Journal of pineal research》2017,62(3)
Melatonin has demonstrated a potential protective effect in central nervous system. Thus, it is interesting to determine whether pre‐ischemia melatonin administration could protect against cerebral ischemia/reperfusion (IR)‐related injury and the underlying molecular mechanisms. In this study, we revealed that IR injury significantly activated endoplasmic reticulum (ER) stress and autophagy in a middle cerebral artery occlusion mouse model. Pre‐ischemia melatonin treatment was able to attenuate IR‐induced ER stress and autophagy. In addition, with tandem RFP‐GFP‐LC3 adeno‐associated virus, we demonstrated pre‐ischemic melatonin significantly alleviated IR‐induced autophagic flux. Furthermore, we showed that IR induced neuronal apoptosis through ER stress related signalings. Moreover, IR‐induced autophagy was significantly blocked by ER stress inhibitor (4‐PBA), as well as ER‐related signaling inhibitors (PERK inhibitor, GSK; IRE1 inhibitor, 3,5‐dibromosalicylaldehyde). Finally, we revealed that melatonin significantly alleviated cerebral infarction, brain edema, neuronal apoptosis, and neurological deficiency, which were remarkably abolished by tunicamycin (ER stress activator) and rapamycin (autophagy activator), respectively. In summary, our study provides strong evidence that pre‐ischemia melatonin administration significantly protects against cerebral IR injury through inhibiting ER stress‐dependent autophagy. Our findings shed light on the novel preventive and therapeutic strategy of daily administration of melatonin, especially among the population with high risk of cerebral ischemic stroke. 相似文献
985.
The effects of heat treatment on the antigenicity and potential allergenicity of α-Lactalbumin (α-LA), β-Lactoglobulin (β-LG), α-casein (α-CN), and β-casein (β-CN) in milk protein concentrates (MPCs) were investigated at temperatures in the range of 65–100°C for times from 10 to 30?min. The antigenicity and potential allergenicity of α-LA decreased significantly. The antigenicity of β-LG was sharply increased throughout the heat treatment, while the potential allergenicity decreased significantly only at 85°C and 100°C for 25?min. The antigenicity of α-CN and β-CN showed fluctuated changes, but were all lower than untreated sample. The α-CN potential allergenicity decreased when heated at 65°C and 70°C for 25?min. Compared with untreated sample, the potential allergenicity of β-CN increased sharply after heat treatment. The results showed that different proteins in the MPCs showed different sensitivities under heat treatment. 相似文献
986.
目的 心肺复苏Utstein评价模式已被许多国家广泛用于心肺复苏评价研究.本文以心肺复苏结果Utstein评价模式设计心肺复苏注册登记表,以评价中国海南海南省人民医院心搏骤停患者流行病学特征、心肺复苏效果与影响因素.方法 应用心肺复苏Utstein模式注册登记表,对海南省人民医院急诊科511例心肺复苏患者进行前瞻性观察研究,评价本组患者心搏骤停流行病学特征及心肺复苏结果.结果 注册登记的511例心肺复苏患者纳入研究.本研究患者以40 ~ 70岁等年龄段心搏骤停发生率较高.既往史中,心血管系统疾病(190例,37.2%)、脑血管疾病(48例,9.4%)及呼吸系统疾病(39例,7.6%)等慢性疾病较为常见.173例(33.9%)为心源性心搏骤停,其中109例(21.3%)为急性心肌梗死.80例(15.7%)患者首次监测心律为心室纤颤.院内心搏骤停患者自主循环恢复率及成活出院率分别为47.0%和13.5%,院外心搏骤停患者为16.7%和4.7%.结论 本研究表明心血管系统疾病、脑血管疾病及呼吸系统疾病为最常见慢性疾病.急性心肌梗死、中风及创伤为最常见心搏骤停病因.院内心搏骤停组自主循环恢复率及成活出院率均高于院外心搏骤停组,两组差异具有统计学意义. 相似文献
987.
Shaowei Cheng Shi Lian Yongjing Hao Nan Kang Shujuan Li Yanjun Nie Fan Zhang 《Photodermatology, photoimmunology & photomedicine》2010,26(4):177-181
Background: Sun exposure can cause a range of skin disorders. Skin damage can be prevented by following certain sun‐protection measures. However, the majority of reported studies regarding sun‐exposure knowledge and behavior have involved Caucasian populations. Methods: A self‐administered multiple‐choice questionnaire was administered. The questionnaire consisted of 13 questions aimed at evaluating people's knowledge, awareness, and protection behavior regarding sun exposure, and their knowledge of sunscreens and sunscreen use. Results: A total of 623 volunteers were enrolled, including 238 men (38.2%) and 385 women (61.8%). The percentages of correct answers regarding sun‐exposure knowledge and awareness ranged from 50% to 80%. Overall, 58.8% used sunscreen as a sun‐protection measure in daily life, followed by use of protective clothes (49.3%), sun umbrella (45.4%), sunglasses (45.3%), and hat (42.2%). Fifty‐two percent thought that suntan was harmful or not attractive. The mean sun‐protection factor (SPF) of the sunscreens used was 27.7 ± 9.2 and the mean UVA protection grade (PA) was 2.3 ± 0.6. Conclusions: Knowledge and awareness concerning the harmful effects of sun exposure are widespread among the Chinese population. Sunscreens with high SPF and PA are the most commonly used among Chinese people. Clear sex differences were observed. There is a significant difference in the attitude toward suntan between Chinese and Caucasian populations. 相似文献
988.
989.
H. Shi 《Physiology & behavior》2009,97(2):199-204
Obesity and its associated health disorders and costs are increasing. Males and females differ in terms of how and where body fat is stored, the hormones they secrete in proportion to their fat, and the way their brains respond to signals that regulate body fat. Fat accumulation in the intra-abdominal adipose depot is associated with the risk for developing cardiovascular problems, type-2 diabetes mellitus, certain cancers and other disorders. Men and postmenopausal women accumulate more fat in the intra-abdominal depot than do pre-menopausal women, and therefore have a greater risk of developing metabolic complications associated with obesity. The goal of this review is to explore what we know about sexual dimorphisms in adipose tissue accrual and deposition. Elucidating the mechanisms by which sex hormones may modulate the way in which fat is accumulated and stored is a critical area of research due to the prevalence of obesity and the metabolic syndrome, and the rapid increase in propensity for these diseases following menopause. 相似文献
990.